Re: I tried it last week and then could not get the
filler out (speedball brand).

I KNOW the answer to this question. You need to buy the product "Greased
Lightning." It comes in a spray. Spray it on, wait 5 minutes and rinse. It
clears the screen like magic.

The old drawing fluid used to wash out with laundry detergent. The new
stuff does not budge with detergent. If you read the label, you'll see that
it calls for "Greased Lightning." I had never heard of it, but now I see it
everywhere.
Christa